Description

Network TCP/IP interface providing a client/server architecture [v25.12.0].

Overview

The Network TCP/IP interface provides a complete networking system based on TCP/IP client/server architecture. It is based on CRM32Pro INetwork code with several parts reworked from scratch and others heavily improved.

Server modes

Key features

High performance: Low latency networking system
Multi-client: Support for up to 8 simultaneous clients
Authentication: Optional password login system (can be enabled or disabled)
Secure transmission: Protection layer to prevent information exposure, modification or hacking
Diagnostics: Log system with optional debugging mode, statistics and client latency information
Flexible deployment: Server can run as stand-alone process or shared with a client

Server configuration

Max clients	Up to 8 simultaneous connections
Login system	Optional password authentication (can be enabled or disabled)
Deployment	Stand-alone server process or shared with a client instance

Server modes

The server supports two working modes depending on how client actions are validated:

Non-authoritative mode

Data processing	Sent data is not processed by the server
Client rights	Each client has full rights for performing any action
Client behavior	"I do my action and report it to others"
Use case	Games where clients do not compete for unique items or actions

Authoritative mode

Data processing	Sent data is processed by the server using a callback function that accepts or denies the data
Client rights	Clients cannot perform actions until accepted by the server callback
Client behavior	"Can I do this action?" → wait for server response → proceed if accepted
Use case	Games where clients compete for unique items or actions

Best practices

Choose the appropriate server mode based on your game design requirements
Use authoritative mode when clients compete for unique resources to prevent race conditions
Design callback functions carefully in authoritative mode to avoid impossible situations
Enable the secure transmission layer to protect sensitive game data
Use the statistics and latency information to monitor network performance
Enable the debug logging mode during development to diagnose connection issues
Consider running the server as a stand-alone process for production deployments
Access the interface exclusively through Main::INetTCP()

Note: The Network TCP/IP interface is a singleton, automatically created once Main is instantiated. You can get a reference to this interface using Main::INetTCP() method.
The Network TCP/IP interface is automatically released when Main::Terminate() is called. At this time, any resource still loaded will be released, avoiding resource leaks.

Classes
class	CRM64Pro::NetTCP
	NetTCP class. More...

Macros
#define	NETFEATURE_DISABLE_LOGIN 1

Enumerations
enum	CRM64Pro::eNetMsg { CRM64Pro::NETMSG_NOTHING = 0 , CRM64Pro::NETMSG_DATA = 64 , CRM64Pro::NETMSG_DATA_ACCEPTED = 66 , CRM64Pro::NETMSG_DATA_DENIED = 67 , CRM64Pro::NETMSG_NEWCLIENT = 132 , CRM64Pro::NETMSG_QUITCLIENT = 133 , CRM64Pro::NETMSG_CLOSE = 134 , CRM64Pro::NETMSG_INFO = 135 , CRM64Pro::NETMSG_PING = 136 , CRM64Pro::NETMSG_ERROR = 192 }
	Network messages. More...

Functions
Sint32	CRM64Pro::NetTCP::info (Sint32 iMode=0)
	Request NetTCP Interface information.
Sint32	CRM64Pro::NetTCP::init (Uint8 iLM)
	Initialize the NetTCP system.
Sint32	CRM64Pro::NetTCP::close ()
	Close the NetTCP system.
Sint32	CRM64Pro::NetTCP::isServer ()
	Check if the server is running.
Sint32	CRM64Pro::NetTCP::isClient ()
	Check if the client is running.
Uint32	CRM64Pro::NetTCP::getIP ()
	Get the IP address.
Sint32	CRM64Pro::NetTCP::getClientName (string &sClientName)
	Get the client name.
Sint32	CRM64Pro::NetTCP::features (Sint32 iFeatures)
	Set or get advance features.
Sint32	CRM64Pro::NetTCP::connectTo (const string &sHost, Uint16 iPort, const string &sClient, Uint32 iPasswd)
	Connect to a server.
Sint32	CRM64Pro::NetTCP::sendData (void *pData, Sint32 iSize, Uint8 bIsQuery=1)
	Send a data package (blocking method).
eNetMsg	CRM64Pro::NetTCP::receiveData (void *pData, Uint32 iSize)
	Receive a data package (non-blocking method).
Sint32	CRM64Pro::NetTCP::freeData (void *&pData)
	Free a received data package.
Sint32	CRM64Pro::NetTCP::queryKillServer ()
	Query to close the server (and all the connected clients).
Sint32	CRM64Pro::NetTCP::queryKillClient ()
	Query to kill this client.
Sint32	CRM64Pro::NetTCP::queryClientsInfo ()
	Query to get updated the information of all connected clients.
Sint32	CRM64Pro::NetTCP::getClientsInfo (ClientInfo **cinfo)
	Get information stored locally about all connected clients.
Sint32	CRM64Pro::NetTCP::setTimeOut (Sint32 iMs)
	Set the connection timeout.
Sint32	CRM64Pro::NetTCP::setSimDelay (Sint32 iMs, Sint32 iMode=0)
	Simulate a connection delay.
Sint32	CRM64Pro::NetTCP::createServer (Uint16 iPort, Sint32 iPasswd, Sint32 iDedicated)
	Create a server.
Sint32	CRM64Pro::NetTCP::setCoreServerCallback (Sint32(myCoreServer)(void pData, Sint32 iSize, void pObj), void pObj=nullptr)
	Set a callback function into the server thread for handling data.

Macro Definition Documentation

◆ NETFEATURE_DISABLE_LOGIN

#define NETFEATURE_DISABLE_LOGIN 1

Used with Features() method. Disables the log into the server for new clients

Enumeration Type Documentation

◆ eNetMsg

enum CRM64Pro::eNetMsg

Network messages.

Enumerator
NETMSG_NOTHING	No message received.
NETMSG_DATA	User data received, pData has it!
NETMSG_DATA_ACCEPTED	Data sent by us was accepted, pData has it.
NETMSG_DATA_DENIED	Data sent by us was denied, pData has the it.
NETMSG_NEWCLIENT	New client connected, pData has the client name.
NETMSG_QUITCLIENT	A client has exited, pData has the client name.
NETMSG_CLOSE	Server has closed us.
NETMSG_INFO	After request a fresh client info, it has arrived and ready to be check with getClientsInfo().
NETMSG_PING	Periodic ping that the server send us.
NETMSG_ERROR	Error, it usually means the client lost the connection with the server.

Function Documentation

◆ info()

Sint32 CRM64Pro::NetTCP::info ( Sint32 iMode = 0 )

Request NetTCP Interface information.

Writes information to the default log.

Parameters

iMode unused for the time being.

Returns: 0 on success, or a negative error code on failure.

◆ init()

Sint32 CRM64Pro::NetTCP::init ( Uint8 iLM )

Initialize the NetTCP system.

Before using createServer() or connectTo(), NetTCP must be initialized.

Parameters

iLM	dedicated network log mode. Check LM_NULL, LM_STDOUT, LM_FILE, LM_FILEAPPEND and LM_CONSOLE (can be OR'ed). Default is LM_NULL.

Returns: 0 on success, or a negative error code on failure.

◆ close()

Sint32 CRM64Pro::NetTCP::close ( )

Close the NetTCP system.

Returns: 0 on success, or a negative error code on failure.

◆ isServer()

Sint32 CRM64Pro::NetTCP::isServer ( )

Check if the server is running.

Returns: 0 server is not runinng or 1 when it is.

◆ isClient()

Sint32 CRM64Pro::NetTCP::isClient ( )

Check if the client is running.

Returns: 0 client is not runinng or 1 when it is.

◆ getIP()

Uint32 CRM64Pro::NetTCP::getIP ( )

Get the IP address.

Returns: return the IP v4.

◆ getClientName()

Sint32 CRM64Pro::NetTCP::getClientName ( string & sClientName )

Get the client name.

Parameters

sClientName a string containing the client name when it is connected to a server.

Returns: 0 on success, or a negative error code on failure.

◆ features()

Sint32 CRM64Pro::NetTCP::features ( Sint32 iFeatures )

Set or get advance features.

Check NETFEATURE_x defines for supported features.

Parameters

iFeatures 32bits signed integer with desired flags. Enabling an already enabled flag disables it. Use -1 to only get current flags.

Returns: greater than 0 on success (current features) or a negative error code on failure.

◆ connectTo()

Sint32 CRM64Pro::NetTCP::connectTo	(	const string &	sHost,
		Uint16	iPort,
		const string &	sClient,
		Uint32	iPasswd )

Connect to a server.

This method will try to connect to the server during the timeout (set by SetTimeOut()) before to return with an error. With ESCAPE key it halts the attempt.

Parameters

sHost	host name or IP of the server to connect to.
iPort	the listening server port (1024 to 65536).
sClient	client name, must be unique and with a maximum of 16 characters.
iPasswd	password to connect to the server.

Returns: 0 on success, or a negative error code on failure.

◆ sendData()

Sint32 CRM64Pro::NetTCP::sendData	(	void *	pData,
		Sint32	iSize,
		Uint8	bIsQuery = 1 )

Send a data package (blocking method).

Sends data to server. Behavior depends on server mode: Authoritative mode evaluates data via CoreServer callback (accepted: sent to all clients; rejected: discarded with notification; bypass with bIsQuery=0). Non-Authoritative mode sends to all clients except sender.

Parameters

pData	pointer to your data.
iSize	size in bytes of your data.
bIsQuery	for Authoritative mode only. Default 1 allows callback evaluation. Other values bypass evaluation.

Returns: 0 on success, or a negative error code on failure.

◆ receiveData()

eNetMsg CRM64Pro::NetTCP::receiveData	(	void **	pData,
		Uint32 *	iSize )

Receive a data package (non-blocking method).

Data packages come from server or other clients. Incoming packages are queued; call repeatedly until return value is 0.

Parameters

pData	pointer to received data package.
iSize	pointer to integer with size of received data.

Returns: check eNetMsg for further information. When NETMSG_NOTHING is returned, pData and iSize are nullptr.

Note: Data is auto-allocated but after receiving via this method, YOU MUST call freeData() when done to avoid memory leaks.

◆ freeData()

Sint32 CRM64Pro::NetTCP::freeData ( void *& pData )

Free a received data package.

Do no try to use any other free function for removing this data and use this method for it.

Parameters

pData pointer to the received data.

Returns: 0 on success, or a negative error code on failure.

◆ queryKillServer()

Sint32 CRM64Pro::NetTCP::queryKillServer ( )

Query to close the server (and all the connected clients).

Returns: 0 on success(next receiveData() will return an NETTCP_ERROR code) or a negative error code on failure.

◆ queryKillClient()

Sint32 CRM64Pro::NetTCP::queryKillClient ( )

Query to kill this client.

Returns: 0 on success(next receiveData() will return an INETWORK_ERROR code) or a negative error code on failure.

◆ queryClientsInfo()

Sint32 CRM64Pro::NetTCP::queryClientsInfo ( )

Query to get updated the information of all connected clients.

Returns: 0 on success, or a negative error code on failure.

◆ getClientsInfo()

Sint32 CRM64Pro::NetTCP::getClientsInfo ( ClientInfo ** cinfo )

Get information stored locally about all connected clients.

Client info table auto-updates on connect/disconnect. For real latency, call queryClientsInfo() first (not needed if client runs with server).

Parameters

cinfo pointer to the information. See sClientInfo struct.

Returns: positive integer with number of clients (for browsing cinfo) on success or a negative error code on failure.

◆ setTimeOut()

Sint32 CRM64Pro::NetTCP::setTimeOut ( Sint32 iMs )

Set the connection timeout.

Parameters

iMs	timeout in milliseconds for connectTo(). Minimum 500ms. Default 2000ms.

Returns: 0 on success, or a negative error code on failure.

◆ setSimDelay()

Sint32 CRM64Pro::NetTCP::setSimDelay	(	Sint32	iMs,
		Sint32	iMode = 0 )

Simulate a connection delay.

Only works for clients. Can be changed at any time.

Parameters

iMs	simulated delay in milliseconds [0-2500]. Default 0.
iMode	Reserved for future use.

Returns: 0 on success, or a negative error code on failure.

◆ createServer()

Sint32 CRM64Pro::NetTCP::createServer	(	Uint16	iPort,
		Sint32	iPasswd,
		Sint32	iDedicated )

Create a server.

Parameters

iPort	the listening server port (1024 to 65536).
iPasswd	integer with the server password.
iDedicated	1 for stand-alone mode (call blocks until server closes). 0 for threaded mode (call returns immediately).

Returns: 0 on success, or a negative error code on failure.

Note: Only one server can be created.

◆ setCoreServerCallback()

Sint32 CRM64Pro::NetTCP::setCoreServerCallback	(	Sint32(*	myCoreServer )(void pData, Sint32 iSize, void pObj),
		void *	pObj = nullptr )

Set a callback function into the server thread for handling data.

Parameters

myCoreServer	callback function taking data pointer, size, and optional pObj. With callback, server runs in authoritative mode; without, non-authoritative mode. Use nullptr to disable callback. Runs on server thread. Return 0 for accepted data or negative for denied.
pObj	pointer to data/function/static method. Default nullptr (unused).

Returns: 0 on success, or a negative error code on failure.

Description

Overview

Key features

Server configuration

Server modes

Best practices

Classes

Macros

Enumerations

Functions

Macro Definition Documentation

◆ NETFEATURE_DISABLE_LOGIN

Enumeration Type Documentation

◆ eNetMsg

Function Documentation

◆ info()

◆ init()

◆ close()

◆ isServer()

◆ isClient()

◆ getIP()

◆ getClientName()

◆ features()

◆ connectTo()

◆ sendData()

◆ receiveData()

◆ freeData()

◆ queryKillServer()

◆ queryKillClient()

◆ queryClientsInfo()

◆ getClientsInfo()

◆ setTimeOut()

◆ setSimDelay()

◆ createServer()

◆ setCoreServerCallback()